CN115910718A - Arc extinguishing system and circuit breaker for a circuit breaker - Google Patents

Abstract

The invention discloses an arc extinguishing system for a circuit breaker, which comprises at least two supporting plates, at least two arc extinguishing grids, and at least two arc converging plates; the arc extinguishing grids are arranged vertically at the rear of the supporting plates Or/and at the front, the arc concentrating plates are respectively arranged on the front of the supporting plate with a space channel left in the middle, the height of the arc concentrating plates is higher than 40% of the height of the arc extinguishing system, and the arc concentrating plates are provided with extinguishing The arc system forms a T-shaped channel. The arc extinguishing system of the present invention is formed with a T-shaped channel, and the upper horizontal channel is used as a pressure relief channel to avoid damage to parts such as the arc extinguishing system and the casing caused by excessive arc voltage in the lower vertical channel; the arc flows from the vertical channel to the horizontal channel The air pressure difference is formed, which is conducive to the rapid extinguishing and discharge of the arc. At the same time, the arc moves upward under the drive of the airflow, which can lead the arc to the upper part and improve the utilization rate of the upper arc extinguishing grid.

Description

Arc extinguishing system and circuit breaker for a circuit breaker

technical field

The invention relates to the technical field of low-voltage electrical appliances, in particular to an arc extinguishing system of a circuit breaker and the circuit breaker.

Background technique

In the industrial low-voltage power system, the universal circuit breaker, as an important part of the power distribution network, is used to distribute electric energy, connect and break the current in the grid circuit, and protect the line and power supply equipment from overload, undervoltage, short circuit, The hazards of faults such as single-phase grounding, the function of breaking the overload or short-circuit current of the circuit breaker is mainly completed by the arc extinguishing system installed in the circuit breaker. When a fault current occurs in the circuit and the current value exceeds the set protection range of the circuit breaker, the tripping mechanism is driven to make the dynamic and static contacts of the circuit breaker disconnect quickly. At this time, the voltage between the dynamic and static contacts causes The air medium discharges to generate a high temperature arc. On the one hand, the arc causes the air temperature in the arc extinguishing device to rise sharply during the combustion process, thereby accelerating air ionization. On the other hand, driven by the magnetic field and fluid effect in the arc extinguishing system, the arc is divided into multiple short arcs by multiple arc barriers, and the deionization effect of the arc is strengthened by the metal arc barriers, the arc becomes smaller and the voltage Raise rapidly to extinguish the arc.

The existing arc extinguishing system technology has the following problems:

1. In existing circuit breakers, under a relatively high rated working voltage, in order to ensure the breaking capacity, the arc channel is often compressed, and gas-generating materials are arranged on both sides of the contact; due to the compression of the arc channel, a huge air pressure is generated when breaking , will impact the parts of the arc extinguishing system, and at the same time, it is easy to cause the arc to spray to the rear of the moving contact. The arc cannot quickly pass through the grid cutting and cooling, and the arc voltage drops, resulting in breaking failure.

2. Due to the limitation of opening distance, when breaking, the moving contact cannot lead the arc to the uppermost grid of the arc extinguishing system, and the utilization rate of the grid is not high, which greatly reduces the arc extinguishing effect.

3. When an arc is generated when the contacts are separated and reaches the arc extinguishing grids, the arc cannot effectively contact the arc extinguishing grids on both sides, and the arc forms a breakdown between the arc extinguishing grids, reducing the arc voltage.

Contents of the invention

Based on the above background, the present invention provides an arc extinguishing system for a circuit breaker. There is a space channel in the middle of the arc concentrating plate and its height is higher than 40% of the height of the arc extinguishing system, so that the arc extinguishing system forms a T-shaped channel, and the upper transverse channel serves as The pressure relief channel avoids damage to parts such as the arc extinguishing system and the casing caused by excessive arc voltage in the lower vertical channel, and can effectively overcome at least one of the above-mentioned problems.

Technical scheme of the present invention is as follows:

In one aspect, the present invention provides an arc extinguishing system for a circuit breaker, comprising at least two support plates, at least two arc extinguishing grids, and at least two arc concentrating plates; the arc extinguishing grids are arranged vertically on the support plate The rear or/and front of the arc extinguishing system, the arc concentrating plates are respectively arranged on the front of the support plate and there is a space channel in the middle, the height of the arc concentrating plates is higher than 40% of the height of the arc extinguishing system, and the arc concentrating plates are provided with The arc extinguishing system of the board forms a T-shaped channel.

In a preferred embodiment, two arc concentrating plates form a vertical channel, and the distance W2 of the vertical channel to the arc extinguishing gas outlet is not less than 1/3 of the length W1 of the arc extinguishing system.

In a preferred embodiment, the transverse channel is formed by two supporting plates, the width of the transverse channel is set as W1, and the width of the vertical channel is set as W2, then W1≥2W2.

In a preferred embodiment, the transverse channel is formed by two supporting plates, the height of the transverse channel is set as H1, and the height of the vertical channel is set as H2, then H1≤1/2H2.

In a preferred embodiment, an accommodating cavity for accommodating the legs of the arc extinguishing grid is formed on the arc concentrating plate.

In a preferred embodiment, the arc concentrating plate includes a vertical plate, a top plate and a base plate, and the vertical plate, the top plate and the base plate are jointly enclosed to form the accommodating chamber.

In a preferred embodiment, a plurality of ribs are arranged on the base plate, and slots are formed between the plurality of ribs.

In a preferred embodiment, the legs of at least two arc extinguishing grids are isolated and insulated from each other.

In a preferred embodiment, the arc concentrating plate is made of non-metallic material.

In a preferred embodiment, the non-metallic material is DMC, nylon, POM, JPO or glass epoxy laminate.

In a preferred embodiment, it also includes a cover plate and a connecting plate, the top of the cover plate is provided with a ventilation hole, and the cover plate is detachably connected to the hole of the connecting plate through screws.

In a preferred embodiment, it also includes a filter assembly, the filter assembly is composed of an upper filter plate, a lower filter plate, an upper pad frame, and a lower pad frame, and the filter screen assembly is arranged on the connecting plate between the cover plate.

On the other hand, the present invention also provides a circuit breaker, including the arc extinguishing system, the contact system, the tripping system and the operating mechanism, the contact part of the contact system protrudes into the middle of the arc concentrating plate space channel.

The beneficial effects of the present invention are as follows:

1. The arc extinguishing system forms a T-shaped channel, and the upper horizontal channel is used as a pressure relief channel to avoid damage to the arc extinguishing system, the casing and other parts caused by excessive arc voltage in the lower vertical channel.

2. The upper and lower parts of the T-shaped channel of the arc extinguishing system form a pressure difference, and the arc moves upward under the drive of the airflow, which can lead the arc to the upper part and improve the utilization rate of the upper arc extinguishing grid.

3. The arc flows from the two channels of the horizontal channel and the vertical channel to the rear of the arc extinguishing system, which is conducive to the rapid extinguishment and discharge of the arc and avoids the arc blowback.

4. The legs of the arc extinguishing grid are separated and insulated from each other, which can prevent the arc from breaking down and connecting in series at the legs of the arc extinguishing grid, and at the same time prevent the moving contact from breaking down with the arc extinguishing grid at the opening position, reducing the arc voltage.

5. A plurality of ribs are set on the arc converging plate to play a reinforcing role, so that the arc converging plate is not easy to be deformed or broken under high temperature arc voltage, ensuring the reliability of the arc channel.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic cross-sectional structure diagram of the arc extinguishing system of the present invention.

Fig. 2 is a schematic perspective view of the arc extinguishing system of the present invention.

Fig. 3 is an exploded schematic view of the arc extinguishing system of the present invention.

Fig. 4 is a schematic structural diagram of the first arc extinguishing grid of the present invention.

Fig. 5 is a schematic structural diagram of the second arc extinguishing grid of the present invention.

Fig. 6 is a schematic structural view of the arc starting plate of the present invention.

Fig. 7 is a schematic structural diagram of the arc concentrating plate of the present invention.

Fig. 8 is a schematic diagram of the principle of air blowing enhancement in the present invention.

Fig. 9 is a schematic diagram of the size of the T-shaped channel of the arc extinguishing system of the present invention.

Fig. 10 is a schematic diagram of the structure of the gas outlet of the arc extinguishing chamber of the present invention.

In the figure: 2 upper cover plate, 201 upper cover plate ventilation hole, 3 filter screen assembly, 301 upper filter screen, 302 upper pad frame, 303 lower pad frame, 304 lower filter screen, 4 connecting plate, 5 screw, 6 support piece , 7 the first arc extinguishing grid, 703 the first leg, 704 the second leg, 8 the second arc extinguishing grid, 803 the third leg, 804 the fourth leg, 9 arc bundle plate, 901 base plate, 902 Cover hole, 903 slot, 904 top plate, 905 vertical plate, 11 arc strike plate.

Detailed ways

Features and exemplary embodiments of various aspects of the invention will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by showing examples of the present invention. The present invention is by no means limited to any specific configuration set forth below, but covers any modification, substitution and improvement of elements, components without departing from the spirit of the invention. In the drawings and the following description, well-known structures and techniques have not been shown in order to avoid unnecessarily obscuring the present invention.

As shown in Figure 1-10, this embodiment discloses an arc extinguishing system for a circuit breaker, which includes two supporting plates 6 located on the left and right sides, two arc concentrating plates 9 located on the left and right sides, sequentially from top to bottom The set arc extinguishing grid 11, the first arc extinguishing grid group, and the second arc extinguishing grid group, the first arc extinguishing grid group includes a plurality of first arc extinguishing grids 7, and the second arc extinguishing grid The sheet group includes a plurality of arc extinguishing grids 8 , and the two sides of the arc leading plate 11 , the first arc extinguishing grid 7 and the second arc extinguishing grid 8 are fixed by the support plate 6 .

The first arc extinguishing grid 7 and the second arc extinguishing grid 8 are arranged at the rear between the support plates 6 on the left and right sides, and the two arc concentrating plates 9 are located between the support plates 6 on the left and right sides. At the front, there is a space channel between the two arc concentrating plates 9, the height of the arc concentrating plates 9 is higher than 40% of the height of the arc extinguishing system, that is, the height of the arc concentrating plates 9 is greater than 40% of the The height of the arc extinguishing system, a vertical channel with a certain depth is formed between the two arc concentrating plates 9, and a horizontal channel with a large width is formed between the upper part of the front part of the two support plates 6, and the vertical channel It communicates with the transverse channel and jointly forms a T-shaped channel of the arc extinguishing system. Wherein the distance W2 of the vertical channel to the direction of the arc extinguishing gas outlet is not less than 1/3 of the length W1 of the arc extinguishing system, the width of the horizontal channel is set to L2, and the width of the vertical channel is set to L1, then L2≥ 2L1; the height of the horizontal channel is set to H2, the height of the vertical channel is set to H1, then H2≤1/2H1, the advantage of this setting is that the height of the vertical channel can ensure that the moving contact and the static contact The opening distance should be set so that the arc generated when the dynamic and static contacts are separated is located in the vertical channel. For the T-shaped channel of the arc extinguishing system, the upper horizontal channel is a pressure relief channel to avoid damage to the arc extinguishing system, the casing and other parts caused by excessive arc voltage in the narrow vertical channel at the lower part.

Figure 8 is a schematic diagram of the principle of air blowing enhancement of the present invention, as shown in Figure 8, the width of the transverse channel at the top of the T-shaped channel is more than 2 times the width of the vertical channel at the bottom, so that there is a gap between the transverse channel and the vertical channel The air pressure difference is formed, and the arc moves upward under the drive of the airflow, which can lead the arc to the upper part and improve the utilization rate of the upper arc extinguishing grid.

As shown in Figure 2, the T-shaped channel forms the upper horizontal channel and the lower vertical channel, and the arc can flow from the vertical channel and the horizontal channel to the rear of the arc extinguishing system, which is conducive to the rapid extinguishment and discharge of the arc. Eliminates the phenomenon that the arc forms a blowback at the rear of the arc extinguishing system.

As shown in Figure 4 and Figure 5, both the first arc extinguishing grid 7 and the second arc extinguishing grid 8 are U-shaped and have multiple pieces, the first arc extinguishing grid 7 consists of the first base and the The first leg 703 and the second leg 704 on both sides of the first base are composed, and the second arc extinguishing grid 8 is composed of the second base and the third legs 803 and 804 on both sides of the second base. The fourth leg 804 is formed, the lengths of the first leg 703 and the second leg 704 are shorter than the lengths of the third leg 803 and the fourth leg 804, wherein the inner surface of the first leg 703 is connected to the first leg 703 The bottom of the U-shaped groove of an arc extinguishing grid 7 is at an acute angle. When multiple first arc extinguishing grids 7 are stacked, the first leg 703 and the second leg 704 are adjacent to each other in the up and down direction, and the first leg 703 of the plurality of first arc extinguishing grids 7 is adjacent to each other. The first legs 703 of the arc extinguishing grid 7 are stacked alternately left and right, which is beneficial to elongate and cool the arc to increase the arc voltage. The third leg and the fourth leg of the second grid 8 are arranged on both sides of the compression zone , When the moving contact is separated from the static contact, an arc is generated, and the arc can effectively contact the arc extinguishing grids on both sides, which can quickly cool the arc and improve the arc extinguishing effect.

As shown in Fig. 2 and Fig. 7, the arc concentrating plate 9 extends from the entrance of the vertical channel to the bottom of the U-shaped groove of the first arc extinguishing grid 8 in the front and rear direction, and the arc concentrating plate 9 includes a vertical The vertical board 905 that is arranged on both sides of the vertical channel, the top board 904 and the base plate 901 that are positioned above the vertical board 905 and perpendicular to the vertical board 905, and the vertical board 905, the top board 904 and the base board 901 are used for forming In the cavity for accommodating the third leg portion 803 and the fourth leg portion 804 , a plurality of ribs are arranged on the base plate, and slots 903 are formed between the plurality of ribs. The base plate 901 is provided with a cover hole 902, the arc concentrating plate 9 wraps the third leg 803 and the fourth leg 804, and a plurality of ribs make the leg 804 of the second arc extinguishing grid 8 They are separated and insulated from each other to prevent arc breakdown and series connection at the grid legs.

As shown in Figure 7, a plurality of slots 903 are arranged on the arc concentrating plate 9, which play a reinforcing role and are used for inserting the third leg 803 and the fourth leg 804 of the second arc extinguishing grid 8, so that the arc concentrating plate is not easy to Deform or break under high temperature arc voltage to ensure the reliability of the arc channel.

In this embodiment, the arc converging plate 9 is made of non-metallic material, which can be DMC, nylon, POM, JPO or epoxy glass laminated board, and the effect of choosing nylon material is better.

The arc extinguishing system of this embodiment also includes a cover plate 2 located at the rear of the arc extinguishing system, a filter assembly 3 and a connection plate 4, the filter assembly 3 is arranged between the cover plate 2 and the connection plate 4, so The filter assembly 3 is composed of an upper filter plate 301, a lower filter plate 304, an upper pad frame 302 and a lower pad frame 303. The top of the cover plate 2 is provided with a ventilation hole 201, and the cover plate 2 is screwed 5 is detachably connected to the hole 401 of the connecting plate 4.

In this embodiment, when the moving and static contacts of the circuit breaker are closed and opened to generate an arc, the arc is guided by the arc strike plate to pass through the T-shaped channel, and after the arc enters the T-shaped channel and passes through the vertical channel and is compressed, the arc moves The speed is accelerated to enter the transverse passage, and due to the sudden increase of the space of the transverse passage, the cold arc is discharged from the opening filter screen assembly 3 at the end of the transverse passage, which improves the arc extinguishing ability.

The arc generated by the moving contact and the static contact of the circuit breaker during the disconnection process is the melting of the contact surface to form free metal ions, and the metal ions together with the surrounding heated air and the arc concentrating plate generate an arc-extinguishing gas cloud, whose volume passes through Heating and expanding, the part of the moving contact extends into the narrow and compact vertical channel a1 formed by the arc converging plate. When the pressure in the vertical channel a1 increases, the arc gas cloud pressure and temperature in the vertical channel a1 Gradually rises to form higher high-temperature and high-pressure gas. As the space at the rear of the arc concentrating plate becomes larger, the arc enters the larger space at the rear of the arc converging plate from the narrow vertical passage. The air pressure difference is formed between the large spaces, so that the arc in the vertical channel quickly enters the larger space behind it, and the arc extinguishing grid assembly quickly cools the arc. Since the two legs of the arc extinguishing grid are staggered, the front end of the arc strike plate is provided with a small angle 111, so that when the movable contact and the static contact are opened, there will be no interference between the movable contact and the arc strike plate. The contact spacing between the moving and stationary contacts will not be affected.

The structures, proportions, sizes, quantities, etc. shown in the drawings attached to the embodiments of the present invention are used to match the content disclosed in the specification, for those who are familiar with this technology to understand and read, and are not used to limit the implementation of the present invention Therefore, it has no technical practical significance. Any modification of structure, change of proportional relationship or adjustment of size shall fall within the scope of this invention without affecting the effect and purpose of the present invention. within the scope covered by the technical content disclosed by the invention. The current embodiments are to be considered in all respects as illustrative rather than restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and falls within the meaning and range of equivalents of the claims All modifications are thereby included within the scope of the present invention.

Claims (13)

1. An arc extinguishing system of a circuit breaker comprises at least two supporting plates, at least two arc extinguishing grid plates and at least two arc collecting plates; arc extinguishing bars piece arrange the setting from top to bottom in the rear portion of backup pad or/and front portion, electric arc bundling plate sets up respectively and leaves the space passageway in the front portion of backup pad and the centre, electric arc bundling plate highly be higher than 40% of arc extinguishing system height, its characterized in that: the arc extinguishing system provided with the arc collecting plate forms a T-shaped channel.

2. The arc extinguishing system of claim 1, wherein: two arc bundling plates form a vertical channel, and the distance W2 from the vertical channel to the direction of the arc extinguishing air outlet is not less than 1/3 of the length W1 of the arc extinguishing system.

3. The arc extinguishing system of claim 2, wherein: and two support plates form a transverse channel, the width of the transverse channel is set to be L2, the width of the vertical channel is set to be L1, and L2 is more than or equal to 2L1.

4. The arc extinguishing system of claim 2, wherein: and two support plates form a transverse channel, the height of the transverse channel is set to be H2, the height of the vertical channel is set to be H1, and H2 is less than or equal to 1/2H1.

5. The arc extinguishing system of claim 1, wherein: and the arc collecting plate is provided with an accommodating cavity for accommodating the leg part of the arc extinguishing grid plate.

6. The arc extinguishing system of claim 5, wherein: the electric arc bundling plate comprises a vertical plate, a top plate and a base plate, wherein the vertical plate, the top plate and the base plate are enclosed together to form the accommodating cavity.

7. The arc extinguishing system of claim 6, wherein: the base plate is provided with a plurality of ribs, and a plurality of slots are formed among the ribs.

8. The arc extinguishing system of claim 1, wherein: the leg parts of at least two arc extinguishing grid plates are mutually separated and insulated.

9. The arc extinguishing system of claim 1, wherein: the electric arc beam concentrating plate is made of non-metal materials.

10. The arc extinguishing system of claim 8, wherein: the non-metallic material is DMC, nylon, POM, JPO or epoxy glass laminate.

11. The arc extinguishing system of claim 1, wherein: the novel electric heating cooker further comprises a cover plate and a connecting plate, wherein the top of the cover plate is provided with an air vent, and the cover plate is detachably connected with the hole of the connecting plate through a screw.

12. The fire extinguishing system of claim 1, wherein: the filter screen assembly is composed of an upper filter screen plate, a lower filter screen plate, an upper cushion frame and a lower cushion frame, and the filter screen assembly is arranged between the connecting plate and the cover plate.

13. A circuit breaker, characterized by: comprising an arc quenching system, a contact system, a trip system and an operating mechanism according to any of claims 1-12, the contact portion of the contact system extending into a spatial channel in the middle of the arc-bundling plate.

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